The present invention relates to the field of company communications, and more especially to company communications systems offering diversified services, of multimedia type for example.
The development of company telecommunication has taken two routes: circuit switching telephony networks and packet switching computer networks.
The architecture of private telephony networks has traditionally been organized around a switching system comprising one or more automatic exchanges or PABX (“Private Automatic Branch eXchange”) connected to a collection of telephone terminals. The deployment of telephone services is implemented by means of signaling information exchanged between a call server, made up of one or more entities of the switching system, the PABX or PABXs and the telephone terminals. A family of communication protocols generally supporting several telephony services is necessary for establishing such exchanges. The ISDN (“Integrated Services Digital Network”) protocols provide such an example of a family of protocols.
The development of new services has led to the incorporation of additional servers into communication systems, these servers being dedicated to these new services (for example voice messaging server, directory server, etc.). The signaling protocols initially designed for call processing functions, for example the H.323 protocol standardized by the International Telecommunications Union, have naturally evolved toward integration of new services.
Other signaling protocols, specific to particular services have been developed, such as for example the DAP (“Directory Access Protocol”) and LDAP (“Lightweight Directory Access Protocol”) protocols specific to the directory services, the SMTP (“Simple Mail Transfer Protocol”) and IMAP (“Internet Message Access Protocol”) protocols specific to messaging, or the HTTP (“HyperText Transfer Protocol”) protocol specific to web browsing, etc. These protocols are customarily used only for the deployment of the corresponding services within data transmission computer networks. Their interoperation with telephony type signaling protocols requires that servers of different kind should be capable of communicating with one another, that is to say that some at least of the servers should be aware of the “jobs” of the other servers. This results in great complexity of the protocols as well as a lack of flexibility when one wishes to upgrade the functions offered.
Moreover, the use of multiple servers dedicated to different jobs often leads the subscribers to carry on a dialog successively with several servers to accomplish a given function, thereby affecting the efficiency and ergonomics of the system.
Within the framework of the web service, it is known to process user requests by interrogating heterogeneous information sources, to translate the various responses and to group them into a data page of a tagging language such as HTML (“HyerText Markup Language”) or XML (“eXtended Markup Language”), which is returned to the user's web browser software. This can be carried out by means of architectures of the three-tier type, as described in the article by C. Petrou et al. “An XML-based, 3-tier Scheme for Integrating Heterogeneous Information Sources to the WWW”, Proc. of the IEEE 10th International Workshop on Database and Expert Systems Applications, 1999, pages 706-710. This makes it possible to process user requests individually, but not to present thereto diversified services to which same has access.
A primary object of the invention is to make the architectures of communication networks more flexible, in the sense that they readily allow the integration of new services or the modification of existing services, by circumventing the specific nature of the interfaces with the servers of various jobs while offering the subscribers considerable functional richness.